CN102232122A

CN102232122A - Nickel material and method for producing nickel material

Info

Publication number: CN102232122A
Application number: CN2009801483321A
Authority: CN
Inventors: 喜多勇人; 香月太; 吉田修二; 滝泽雄一; 有园太策; 奥井利行; 前田尚志; 川本正幸; 细井威男; 山崎正弘
Original assignee: Sumitomo Metal Industries Ltd
Current assignee: Nippon Steel Corp
Priority date: 2008-12-02
Filing date: 2009-12-02
Publication date: 2011-11-02
Anticipated expiration: 2029-12-02
Also published as: CN102232122B; KR20110084320A; KR101311558B1

Abstract

Disclosed is a nickel material which is reduced in defects such as cracks and scratches. Also disclosed is a method for producing a nickel material, in which the formation of the defects can be prevented during the production process, and which can produce a nickel material with good efficiency. The nickel material is characterized by comprising 99 mass% or more of nickel and 3 to 110 ppm (inclusive) of boron.

Description

The manufacture method of nickel material and nickel material

Technical field

The present invention relates to nickel material and manufacture method thereof that the generation of defects in the manufacturing process is suppressed.

Background technology

The nickel material of the sheet material that use nickel forms in the starting material, wire rod and so on is used to various uses.

For example, contain the above nickel material of nickel 99 weight % because excellences such as electroconductibility, physical strength, erosion resistances, thereby be widely used in the inside wiring material (lead-in wire, lug), alkaline-resisting with equipment and materials etc. of battery.

Because the metal that employed nickel is more general than iron, aluminium etc. in the formation of this member is more expensive, thereby when making the nickel material, inhibition generation of defects, the raw-material consumption of reduction become important problem.

The defective that produces when making the nickel material for example can be enumerated and adds the corner crack that produces man-hour, surface spots etc. in hot rolling and result from the surperficial defective of hot rolling product.

As the method that suppresses these defectives, the surface coated antioxidant of known continuous casting plate blank before hot rolling, heating keeps, carries out then hot rolled method (with reference to patent documentation 1) under specified temp.

In addition, as the additive method that suppresses above-mentioned defective, the known method that the composition of nickel material is adjusted, known have a following method: making Mg become 0.005～0.015 quality %, Ti by adjustment becomes 0.005～0.015 quality %, Al and becomes 0.005～0.015 quality %, and then, by adjustment other one-tenth are divided into below the 0.5 quality %, thereby can improve the processibility (with reference to patent documentation 2) when carrying out hot rolling.

In addition, as the other defect that produces in the nickel material, known have a following situation: when containing the sulphur composition in making used starting material, because hot-work causes the segregation in the crystal boundary of nickel material of sulphur composition, makes the ductility reduction of crystal boundary portion, crack when crystal is applied high-speed distortion etc.

As the method that suppresses this defective, adopted the content that makes sulphur composition in the starting material is method below 0.001% in the past.

The prior art document

Patent documentation

Patent documentation 1: the spy of Japan opens clear 63-168259 communique

Patent documentation 2: the spy of Japan opens flat 08-143996 communique

Summary of the invention

The problem that invention will solve

Yet known have a following situation: by apply distortion with lower velocity under specified temp (700 ℃～900 ℃), the nickel material can show the character (medium temperature fragility) of embrittlement of grain boundaries.

Known this medium temperature fragility is owing to the distortion that the heat that produces in the casting process when making the nickel material, the heating process before the rolling processing causes, the isochronous distortion that stretches reduces the ductility (crystal boundary ductility) of crystal boundary to occur to the nickel material with lower velocity.

Therefore, when making the casting product, when the nickel material before the hot rolling is heated, the reason that inside, the surface that might cause embrittlement and become the nickel material cracks etc.

In addition, as mentioned above, under the significantly reduced state of crystal boundary ductility (state of crystal boundary portion embrittlement), the nickel material is rolled (hot rolling, cold rolling) and adds man-hour, the part of embrittlement enlarges or oxidation, thus easily crack on inside, the surface of rolling processed goods (hot rolling product, cold rolling product), defective such as surface spots.

And then, when after rolling processing, carrying out clean annealing (Bright Annealing), also can produce the bubble flaw sometimes on the surface of nickel material.

Above-mentionedly be difficult to be suppressed by above-mentioned hot rolling being added the method that the defective that produces man-hour suppresses by the caused defective of medium temperature fragility.

In addition because medium temperature fragility is not the caused embrittlement of sulphur composition yet, even thereby the content by control sulphur composition also be difficult to suppress medium temperature fragility.

Thereby, produce in the rolling processed goods by the caused defective of medium temperature fragility in order to be suppressed at, adopt the method that is known as slow heat (slow heat).

This slow heat is meant according to heat-up rate to be the mode of low speed, begins method that the nickel material before the hot rolling is heated from lesser temps, thus, reduces the generation of thermal distortion and suppresses the embrittlement of crystal boundary.

Yet, even carry out slowly when hot, also can't suppress the generation of thermal distortion fully, be difficult to prevent fully medium temperature fragility.

And then, carry out slowly when hot, sufficient temperature needs for a long time for being rolled processing until reaching, thereby the productivity of the nickel material non-constant that becomes.

Thereby, the objective of the invention is to, by suppressing the medium temperature fragility of nickel material, thereby provide the less nickel materials of defective such as crackle, flaw, described generation of defects in the time of can suppressing to make is provided simultaneously, and makes the manufacture method of the nickel material of nickel material efficiently.

The scheme that is used to deal with problems

Nickel material of the present invention is characterised in that, contains nickel more than 99% and 3ppm is above and 110ppm is following boron in mass.

In addition, the manufacture method of nickel material of the present invention is characterised in that, makes the nickel that contains in mass 99% or more and 3ppm is above and the slab of the boron below the 110ppm, and this slab is rolled and makes tabular nickel material.

The effect of invention

As mentioned above, according to nickel material of the present invention and manufacture method thereof, by suppressing the medium temperature fragility of nickel material, can provide the less nickel materials of defective such as crackle, flaw, described generation of defects is also made the nickel material efficiently in the time of can suppressing to make simultaneously.

Description of drawings

Fig. 1 is SEM-EDX (scanning electron microscope/power spectrum Conjoint Analysis) wave spectrum of the abrasion powder that produced by the pin disc type friction-wear test (pin-on-disk test) of having used the disk of being made by the nickel cold rolling coil that does not add boron.

Fig. 2 is the SEM-EDX wave spectrum of the abrasion powder that produced by the pin disc type friction-wear test of having used the disk of being made by the nickel cold rolling coil that is added with 15ppm boron.

Figure 3 shows that the chart that utilizes the accumulative total draft (total draft) and the relation of average roll pressure to represent the situation that rolling abrasion powder is piled up on working roll.

Fig. 4 is ESCA (chemical analysis electronic instrument) analytical results: nickel zone (a: white powder, b: product, c in the past: boron adds product).

Fig. 5 is the esca analysis result: boron zone (c: boron adds product).

Fig. 6 is the figure of expression boron addition (B addition) with the relation of surface boron concentration (surperficial B concentration).

Fig. 7 is the figure of the relation of presentation surface boron concentration (surperficial B concentration) and nickel oxide ratio (oxide ratio of Ni).

Embodiment

Below embodiments of the present invention are described.

The nickel material of present embodiment is made by containing as the starting material of the boron that constitutes element beyond the principal constituent nickel.

Particularly, described nickel material is by the starting material that contain nickel more than 99% and the boron more than the 3ppm and below the 110ppm in mass and make.

And then described nickel material also contains impurity except containing as raw-material nickel and the boron.

In order not influence effect of the present invention, preferably the total amount with this impurity is modulated to below the 0.5 quality %.

As this impurity, can enumerate mainly is that necessary element of depickling or unavoidable impurities in the refining procedure is carbon, silicon, manganese, phosphorus, sulphur, copper, magnesium, iron, oxygen etc.

Even the total amount of the content of these unavoidable impurities is adjusted to 0.5 quality % when following, also preferred each composition is following content.

That is, carbon is below 0.02% in mass, is generally about 0.01%.

In addition, silicon is below 0.35%, is generally about 0.03%, and manganese is below 0.35%, is generally about 0.2%.

In addition, phosphorus is below 0.01%, is generally about 0.002%, and sulphur is below 0.01%, is generally about 0.001%.

In addition, copper is below 0.25%, is generally about 0.02%, and magnesium is below 0.1%, is generally about 0.01%.

And then iron is below 0.4%, is generally about 0.1% degree, and oxygen is below 0.005%, is generally about 0.003%.

And then the waste wood (waste material) that utilizes the nickel material is during as starting material, and the impurity of being sneaked into by this waste material also can suitably contain in the nickel material of present embodiment.

The nickel material of present embodiment is cast the defective that produces in product, the rolling processed goods (hot rolling product and cold rolling product) by contain boron in starting material thereby can suppress it.

Particularly, described nickel material is by containing boron as starting material, thereby in its manufacturing process, even under specified temperature, crystal is applied distortion with lower velocity, also can suppress the brittle appearance of medium temperature, thereby can suppress by generation of defects such as the caused crackle of this medium temperature fragility, surface spotses.

Think because following former thereby generation by the defective that described medium temperature fragility causes: owing under specified temperature (700 ℃～900 ℃), the nickel material is applied distortion with lower velocity, so dislocation takes place in crystalline region, on the other hand, crystal dislocation is restricted in crystal boundary portion.

As putting on crystalline lower velocity deformation reason, think the thermal distortion that in casting process, heating process before rolling, produces, the distortion that is produced when the nickel material being stretched etc. with lower velocity.

As known from the above, in order to suppress defective,, also to make the influence of dislocation not concentrate on crystal boundary, can suppress the brittle appearance of medium temperature thus even when importantly crystal being applied the distortion of lower velocity.

Thereby, importantly when making the nickel material, add the boron that contains more than the 3ppm, below the 110ppm in the used starting material.

That is, because in the nickel material, boron exists with the state of segregation in crystal boundary, even thereby when crystal being applied distortion with lower velocity, the influence that also can suppress dislocation concentrates on crystal boundary, can suppress crystal boundary portion ductile and reduce.

Thereby medium temperature fragility is suppressed, and can suppress to produce during fabrication the defectives such as crackle that cause therefrom.

For example, when forging the slab of making the nickel that contains in mass more than 99% and the boron more than the 3ppm and below the 110ppm, when this slab is rolled, can reduce the possibility that cracks and can make the nickel material efficiently.

In addition, boron is given suitable influence by the operability of other effects when rolling.

For example, the nickel material is many to be provided with the high platy morphology of versatility, owing in its industrial production, can make continuously and the productivity excellence, thereby the method for preferred cold rolling one-tenth coiled sheet shape.

But, because nickel is soft metal, and easily coagulating on working roll, thus sometimes in rolling the surface of nickel coiled sheet easily be worn away and produce rolling abrasion powder (following also the abbreviation made " abrasion powder "), and because this abrasion powder and at surface generation cut.

And boron is for the effective composition of the generation that suppresses this abrasion powder.

This is elaborated.

At first, the influence about the abrasion powder describes.

The influence of abrasion powder mainly can roughly be divided into following two kinds according to the difference of its character.

First influence is the bad order of goods, it causes like this: when the aggregation of abrasion powder is higher, form the aggregation block of abrasion powder in the roll gap of the working roll in rolling, this accumulative abrasion pruinescence is transferred to the surface of the nickel material in rolling, and causes the bad order of goods.

Second influence can be listed below: when rolling abrasion powder has surface that is attached to working roll and the character of piling up, cause the surface roughening of working roll and surface luster to be reduced by the abrasion powder of piling up, in addition, rapid increase takes place in frictional coefficient, the thickness of slab change of rolling load increase and coiled sheet length direction; Or since rolling load surpass, thereby be absorbed in can't be rolling situation.

In order to prevent to produce such unacceptable product, for example can enumerate coiled sheet length that restriction is rolled, be absorbed in the rolling method of finishing 1 passage before can't be rolling.

Perhaps, can enumerate the method for operating of frequently carrying out the working roll that the abrasion powder is piled up is taken out, is exchanged into untapped working roll from roller mill as its countermeasure.

Yet undoubted any method all causes significantly productivity reduction.

According to the fact that the inventor found, think that this abrasion powder is following generation: the oxide compound of nickel exerts an influence, and the nickel oxide on nickel material surface and airborne moisture react etc., forms nickel hydroxide, and this nickel hydroxide comes off and produces the abrasion powder.

And, because boron diffusion rate is soon, easily concentrated by the surface, thereby can play a role especially effectively for the formation of the oxide compound that suppresses nickel material surface.

For example, when boracic not, by the rolling fresh surface that exposes, owing to coagulating under the high temperature and high pressure environment of nickel fine particle in the working roll roll gap that abrasion comes off easily oxidized, because the nickel fine particle of this oxidation has aggregation, thereby form thick abrasion powder, may be present in unevenly in the working roll roll gap and produce pattern defect.

On the other hand, the hot rolled coil that contains specified amount boron usually since boron concentrated by the surface, even thereby under the high temperature and high pressure environment in the working roll roll gap, also can suppress the oxidation of nickel.

Particularly under the less rolling condition of contact pressure, do not have the generation of abrasion powder substantially, can reduce the possibility that produces pattern defect.

In addition, the formation of oxyhydroxide also is suppressed, and also can prevent coming off of nickel hydroxide.

That is, can suppress the problem that produced by rolling abrasion powder in the cold rolling coil (nickel material) of manufacturing.

In addition, because avoided the trouble that is caused by the abrasion powder, can make cold rolling coil.

Thereby, restriction is not set, frequently do not change the nickel material that working roll just can be made better quality carrying out cold rolling length.

In addition, in order more positively to obtain this effect, the preferred nickel that contains 99.0% or more and the 4ppm the hot rolled coil above and boron that 100ppm is following of using implemented at least 1 time cold rolling and manufacturing nickel material (cold rolling coil).

The preferred content of boron is that the reason of above-mentioned scope is, when the content of boron is lower value (less than 4ppm), be difficult to make the preferential oxidation effect of boron to bring into play function effectively, might form much nickel oxide on the surface as the root of the nickel hydroxide of the reason material of abrasion powder.

On the other hand, when surpassing 100ppm, may form thick boride and cause the deterioration of processibility, erosion resistance thereby capping value (100ppm).

When this is elaborated, when the nickel coiled sheet of boracic was not rolled in the past, by this rolling fresh surface that exposes, oxidation takes place owing to coagulating under the high temperature and high pressure environment of nickel fine particle in the working roll roll gap that abrasion comes off.

On the other hand, as mentioned above, when hot rolled coil contained boron, usually boron was concentrated on the surface of hot rolled coil, thereby this hot rolled coil was being carried out when cold rolling, thereby this boron can be suppressed the formation of nickel oxide by oxidation preferentially on fresh surface etc.

In addition, like this by containing boron, for example when the thermal treatment the nickel coiled sheet being implemented to be used to anneal etc., on nickel coiled sheet surface, boron is more preferentially oxidized than nickel, forms boron oxide (B ₂O ₃), boron nitride (BN).

And, owing to the former (B ₂O ₃) have the effect of about 450 ℃, fusing and covering nickel coiled sheet surface, thereby can further suppress the formation of nickel oxide.

In addition, under the higher rolling condition of contact pressure, the abrasion of coagulating owing to working roll and coiled sheet surface may produce the fine particle (abrasion powder) that is made of not oxidized nickel.

At this moment, this nickel fine particle is coagulating in roll gap and is being piled up in work roll surface, and the result might cause the increase of rolling load.

Thereby, by containing the boron of any amount in the above-mentioned scope, make the contact pressure between working roll and the rolling stock keep less simultaneously, thereby can more positively prevent the reduction of operability.

More specifically, when after hot rolling, implementing cold rolling more than 1 time, preferably according to the average roll pressure (kgf/mm of each passage ²) the value mode that when the value of the accumulative total draft of establishing this passage is X (%), is no more than 77+0.58X implement cold rolling.

For example, after hot rolling, this hot rolled coil implemented the cold rolling of 1 passage and when making the nickel cold rolling coil, if establish the thickness of slab of hot rolled coil and be T0 (mm), the thickness of slab after cold rolling is T1 (mm), then the accumulative total draft of this 1 passage: X1 (%) is (T0-T1)/T0 * 100 (%).

P1≤77+0.58·X1…(1)

And the value of establishing this average roll pressure in cold rolling is P1 (kgf/mm ²) time, preferably implement cold rolling according to the mode that satisfies above-mentioned formula (1).

In addition, then, for example further implement 2 passages cold rolling, when implement amounting to 3 passages cold rolling, if the thickness of slab of establishing thickness of slab after second passage (appending 1 passage) and being after T2 (mm), the 3rd passage (appending 2 passages) is T3 (mm), the accumulative total draft before second passage then: X2 (%) be (T0-T2)/T0 * 100 (%), and the accumulative total draft the during end of the 3rd passage: X3 (%) is (T0-T3)/T0 * 100 (%).

And, be P2 (kgf/mm if establish the value of the average roll pressure of second passage ²), the value of the average roll pressure of the 3rd passage is P3 (kgf/mm ²), then preferably implement the cold rolling of second passage and the 3rd passage according to the mode that satisfies following formula (2), (3) respectively.

P2≤77+0.58·X2…(2)

P3≤77+0.58·X3…(3)

In cold rolling after hot rolling, in order to satisfy above-mentioned formula (1) etc., the easiest is, and for example the draft of each passage to be restricted to regulation following and to implement multi-pass rolling.

As other method, can enumerate the method that increases rolling tensile force, the method for using the path working roll etc.

In addition, in order to increase oil film thickness in the working roll roll gap, to reduce the rolling friction coefficient, it also is effective using the high viscosity ROLLING OIL or increasing roll speed.

These methods of restriction average roll pressure are not to be defined in aforesaid method, can adopt the whole bag of tricks, but also these method combinations can be implemented.

In addition, the value of average roll pressure can be tried to achieve divided by plate wide [mm] and contact arc length [mm] by rolling load [tonf], is R[mm at the radius of establishing working roll], the thickness of slab reduction is Δ h[mm] time, contact arc length is usually by (R * Δ h) ^0.5And obtain.

In addition, so long as the restriction of reaching this average roll pressure in more than half length of the mill length of cold rolling coil gets final product, even for example in rolling beginning or the acceleration and deceleration portion place when finishing be only limited to and increase rolling load at short notice, the possibility that the possibility that the accumulation of rolling abrasion powder on working roll sharply carried out is also lower, produce pattern defect etc. is also lower.

Thus, as long as about 80% relations that satisfy above-mentioned formula (1) etc. of the length direction central part of formed nickel cold rolling coil, can suppress to follow the problem that accumulation produced of rolling abrasion powder usually.

In addition, identical problem for example also can take place when cold rolling coil is carried out division processing etc. in the formation of the nickel hydroxide on cold rolling coil surface.

For example, in cutting apart cut-out, because pressing plate parts and metal sheet sliding contact, therefore for the surface that prevents metal sheet forms scratch, the contacted contact surface of pressing plate parts and metal sheet forms with fibrous structures such as felts.

But, nickel thin plate etc. is being cut apart when cutting off, produce by the powder that nickel hydroxide caused by the contact position of above-mentioned pressing plate parts and nickel thin plate, sometimes the fine flaw of generation on the nickel thin sheet surface after cutting apart.

For the inhibition of this problem, boron also plays a role effectively.

In addition, in order more positively to prevent the formation of nickel hydroxide, the concentration that preferably makes the most surperficial boron of nickel material is more than the 1 atom %.

The surface of more preferably implementing boron concentrates and makes the concentration of the most surperficial boron is more than the 3 atom %.

For the surface that produces this boron concentrates, thus usually can be by in the non-oxidation environment, the nickel material being heat-treated enforcement.

For example, use in the thermal treatment in the nitrogen, hydrogen, argon gas a kind or with several mixed mixed gass as environmental gas, and use dew point for below-30 ℃, be preferably below-40 ℃, be preferably the environmental gas below-70 ℃ especially, in this environmental gas, the nickel material is heated to more than 450 ℃ and 900 ℃ of following scopes in arbitrary temperature, thereby the surface that can more preferably implement boron concentrates.

The reason that environmental gas preferably has above-mentioned dew point is, when dew point is higher than-30 ℃, significantly carries out owing to moisture contained in the environmental gas causes the oxidation of nickel, might can't obtain to contain the effect of boron.

In addition, for the preferred range of thermal treatment temp, the reason of setting above-mentioned lower value (450 ℃) is, the fusing point of the oxide compound of boron is 450 ℃, under the temperature lower than it, even form the oxide compound of boron, also can't fusion also expand from the teeth outwards, may be present in the part unevenly.

On the other hand, the reason of setting above-mentioned higher limit (900 ℃) is, when when surpassing the temperature of this temperature, the distillation of the oxide compound of boron becomes significantly, might suppress the formation of the surface oxidation overlay film of nickel material fully.

In addition, for which kind of degree is the concentration of the most surperficial boron be concentrated into by the surface value, can implement from the surface of nickel material (nickel thin plate) to the ultimate analysis of the degree of depth (for example to the 5nm degree of depth) of number nanometers by the analytical procedure of utilizing x-ray photoelectron spectroscopy apparatus (XPS/ESCA), Auger electron spectroscopy apparatus (AES) etc., the quantity of calculating the boron atom is with respect to all % and confirming why.

At this moment, when the concentration of the most surperficial boron during less than 1 atom %, then might the surface concentrate not enoughly, the effect of oxidation that suppresses the nickel material be insufficient.

Thereby, preferably according to the boron concentration on surface at least be more than the 1 atom %, the mode that is preferably more than the 3 atom % sets heat-treat condition.

In addition, the upper limit of the concentration of the most surperficial boron is not particularly limited, even but it is concentrated, also be about 20 atom % usually.

For the surface of carrying out this boron concentrates, can enumerate the method that in the nickel material that contains the above nickel of 99.0 quality %, further contains above the boron of 4ppm.

Say that more positively concentrate in order to make boron carry out the surface, preferably making boron content is more than the 6ppm, more preferably more than the 8ppm.

In addition, this moment, boron can form oxide compound (B ₂O ₃) also can form nitride (BN).

Above-mentioned thermal treatment is utilizing the rolling grade of precision work that the thickness of slab of rolling coiled sheet has been implemented to adjust back enforcement usually.In addition, if desired, also can after above-mentioned thermal treatment, implement to be used for the skin-pass that hardness is adjusted, after this skin-pass, also can and then implement shape correction.

The nickel material (thin plate) that forms by carrying out this heat treated manufacture method is cut apart cut-out afterwards when conductor material that is used as battery etc., but because the additive effect of boron, can prevent scratch, simultaneously can the inhibited oxidation overlay film or the formation of oxyhydroxide, can be made into the good goods of weldability.

In addition, be used under this conductor material situation in addition, also might be by punching processing.

For nickel thin plate in the past, when carrying out punching processing repeatedly, the surface the oxidation overlay film peel off, attached on the mould, changed gap (clearance) amount, might end face portion produce shear burr, according to circumstances difference and damage article shape greatly, produce and clamp-on flaw etc.

Yet as above the nickel thin plate of Huo Deing is owing to the effect of boron has the high and stable surface coating of intensity, thereby can implement punching processing with stable status for a long time, also can expect useful effect to the quality of the goods of gained.

In addition, in the present embodiment illustration tabular nickel material, but the scope that the nickel material of various forms such as bar-shaped, tubulose, wire, bulk also belongs to the present invention to be intended to.

Embodiment

Below embodiments of the invention are described.

＜＜estimate 1〉〉

(making of test body)

1. the making of ingot bar

Constitute the mode that composition that following table 1 puts down in writing constitutes according to the composition beyond the nickel, make the ingot bar of 100kg, as a comparative example 1 and 2, embodiment 1～4 by the high frequency vacuum melting.

[table 1]

2. the making of tension test sheet

Under 1200 ℃, above-mentioned each ingot bar is carried out heat forged, make the forging slab of thickness 20mm.In each comparative example and embodiment, make the pole type tension test sheet of diameter 10mm, length 110mm then respectively by this forging slab.In addition, the temperature condition during as heat forged is made according to mode identical between each test film.

3. the making of thermal distortion evaluation test sheet

Cut the square cubes of 100mm by above-mentioned each ingot bar, be coated with antioxidant from the teeth outwards, in each comparative example and embodiment, make thermal distortion evaluation test sheet respectively.

(evaluation test of high temperature ductility)

1. test method

In 1 minute, above-mentioned each tension test sheet intensification is heated to the temperature that following table 2 is put down in writing, kept afterwards 60 seconds.

Then, use each the tension test sheet that heated to carry out tension test.Condition during as each tension test sheet of stretching is tested with the Deformation velocity (draw speed) that following table 2 is put down in writing.

2. evaluation method

Measure cross section decrement (the sectional area reduction of the test body after the tension test accounts for the ratio of the sectional area of the test body before the tension test), carry out the evaluation of crystal boundary ductile.Test-results is shown in following table 2.

[table 2]

(thermal distortion evaluation test)

1. test method

Above-mentioned each thermal distortion evaluation test sheet of normal temperature is disposed in the process furnace that is heated to 1250 ℃, and carrying out rapidly, heat test to each test film reaches till 1250 ℃.In addition, with predetermined heating speed (10 ℃/min) each the thermal distortion evaluation test sheet to normal temperature heats, carry out slow heat test to each test film and reach till 1250 ℃.

2. evaluation method

By forging hammer (press hammer) equipment each the thermal distortion evaluation test sheet that heats back (1250 ℃) is forged, make the thick forged material of 30mm.Then, carry out the permeation flaw detection (penetrant test) (liquid immersion test) in the thick cross section of 30mm of this forged material, estimate the generation state of internal fissure.With the situation that produces internal fissure as the situation of " * ", not generation as " zero ", test-results is shown in the following table 3.

[table 3]

(having used the test of CC slab)

1. the making of test body

According to becoming the mode that composition that following table 4 puts down in writing constitutes, utilize 30 tons electric furnace and continuous casting process casting 150mm thick * the wide CC slab of 1000mm, as a comparative example 3, embodiment 5 and 6.

[table 4]

2. test method and evaluation method

(1) internal fissure evaluation

Permeation flaw detection (liquid immersion test) is carried out in the thick cross section of 150mm of above-mentioned CC slab, the generation state of internal fissure is estimated.With the situation that produces internal fissure as the situation of " * ", not generation as " zero ", test-results is shown in the following table 5.

(2) hot rolling test

Above-mentioned CC slab was disposed in 1250 ℃ the stove 2 hours 30 minutes and heats, carry out hot rolling then and make the thick hot-rolled sheet of 30mm.Then, permeation flaw detection is carried out in the thick cross section of 30mm, the generation state of internal fissure is estimated.With the situation that produces internal fissure as the situation of " * ", not generation as " zero ", test-results is shown in the following table 5.In addition, carry out the evaluation of surface spots with hot plate volume (hot rolled CC slab being wound into the state of coiled sheet shape).Test-results is shown in following table 5.In addition, as the test-results of surface spots, the number of regions of expression generation surface spots accounts for the ratio of the general area number when dividing hot-rolled sheet at interval with 1m in one direction.

(3) cold rolling test

Open above-mentioned hot plate volume, carry out cold rollingly at normal temperatures, make the thick cold-reduced sheet of 0.1mm, carry out the evaluation of bubble flaw.Test-results is shown in following table 5.In addition, as the test-results of bubble flaw, the number of regions of expression generation bubble flaw accounts for the ratio of the general area number when dividing hot-rolled sheet at interval with 1m in one direction.

[table 5]

	The CC slab	Hot-rolled sheet	The hot plate volume	Cold-reduced sheet
						Internal fissure	Internal fissure	Surface spots	The bubble flaw
Comparative example 3	×	×	40％	20％
					Embodiment
5	○	○	3％	0％
					Embodiment 6	○	○	2％	0％

(brief summary)

(1) about the evaluation test of high temperature ductility

When embodiment 1～4 and comparative example 1 and 2 are compared, when Deformation velocity when being high-speed, embodiment 1～4 and comparative example 1 and 2 the two in all temperature provinces, be cross section decrement more than 85%, unconfirmed to the influence that interpolation brought by boron.Think that its reason is, when Deformation velocity when being high-speed, the cross section decrement is subjected to the influence of the amount of sulphur composition, thereby is trace below the 10ppm by the sulphur composition that makes embodiment and comparative example, thereby shows higher cross section decrement.

On the other hand, when Deformation velocity is lower velocity, confirm under the Heating temperature of 700 ℃ and 800 ℃, comparative example 1 and 2 cross section decrement are for significantly being lower than the value of the cross section decrement of embodiment 1～4.Think that its reason is, because the brittle influence of medium temperature, the ductility of the crystal boundary portion of comparative example 1 and 2 test body reduces, the test body becomes fragile, thereby the cross section decrement reduces.

Relative therewith, in all temperature provinces, even when crystal applied the distortion crystal of lower velocity, the cross section decrement of embodiment 1～4 is also up to more than 90%.Think that its reason is,, also do not show medium temperature fragility even under 700 ℃～900 ℃ temperature, applied the nickel material of the distortion of lower velocity.

(2) about the thermal distortion evaluation test

When embodiment 1～4 and comparative example 1 and 2 are compared, when slowly heating, embodiment 1～4 and comparative example 1 and 2 the two all can not produce internal fissure, unconfirmed to the influence that interpolation brought by boron.Think that its reason is,, suppressed the generation of thermal distortion by slow heating.

On the other hand, when heating rapidly, in comparative example 1 and 2, confirm internal fissure, but unconfirmed to internal fissure in embodiment 1～4.Think that its reason is, the thermal distortion that is taken place by heating rapidly (distortion that takes place with lower velocity) puts on the nickel material, shows medium temperature fragility in the test body of comparative example 1 and 2, thereby the embrittlement of crystal boundary portion, causes internal fissure.Relative therewith, in the test body of embodiment 1～4,, thereby do not produce internal fissure even under the state that has applied thermal distortion, do not show medium temperature fragility yet.

(3) about having used the test of CC slab

To embodiment 5 and 6 and comparative example 3 when comparing, confirm in comparative example 3, produce internal fissure in CC slab and the hot-rolled sheet, and do not produce internal fissure in embodiment 5 and 6.In addition, confirm the surface spots that in comparative example 3, has produced the hot plate volume, the bubble flaw of cold-reduced sheet, and in embodiment 5 and 6, do not produce surface spots, bubble flaw fully.

Think that its reason is, the thermal distortion during owing to making CC slab, the test body of comparative example 3 shows medium temperature fragility, thereby the ductility of crystal boundary portion reduces, produces defectives such as internal fissure.Relative therewith, think in the test body of embodiment 5 and 6, even the thermal distortion when making the CC slab puts on the crystalline state, do not show medium temperature fragility yet, thereby do not produce defective such as internal fissure.

(4) as mentioned above, by containing the starting material of boron when making the nickel material more than the 3ppm, even thereby be heated to the nickel material that has applied the lower velocity distortion under 700 ℃～900 ℃ the state, do not show medium temperature fragility yet, thereby crystal boundary ductility do not reduce, and can suppress generation of defects such as internal fissure.

＜＜estimate 2〉〉

Then, the inhibition effect that contains the abrasion powder that boron produces is estimated.

(the effect of adding about boron: the rub(bing)test of pin dish method)

At first, in order to investigate the character of the abrasion powder in cold rolling, utilize the rub(bing)test of pin dish method.

Pin dish method is the general rub(bing)test method that is applicable to that the abrasion amount on the surface of friction is estimated, and is the test method(s) that the end face of the pin of column is made its rotational slide by being pressed in discoideus disc surfaces.

In this evaluation test, use the pin of the quadrangular prism of the length 30mm that from the working roll (being equivalent to SKD11) of reality, cuts with the square cross-sectional shape of 8.8mm.

In addition, disk uses the plectane of the diameter 80mm that cuts two kinds of nickel cold rolling coils (product of annealing) of the about 1mm of thickness that makes from real machine.

Principal constituent beyond the contained nickel of this disk is shown in following table 6.

[table 6]

Disk	C	B	Si	Mn	P	S	Cu	Mg	Cr	Fe
											#
1	0.003	0.0015	0.008	0.130	0.0016	0.0002	0.013	0.0085	0.010	0.049
											#2	0.015	-	0.026	0.148	0.0020	0.0011	0.011	0.0069	0.006	0.143

Numeric representation quality % in the ※ table.

Outside radius vector on the position of the center 25mm of the above-mentioned disk of direction distance, vertically push described pin with respect to disk with load 4kgf, speed with 60rpm under this state makes the disk rotation, thereby the friction between analog operation roller and the nickel cold rolling coil, after making disk rotate 20,000 times, reclaim the abrasion powder that is produced, carry out compositional analysis and morphologic observation.

In addition, in order to promote the generation of abrasion powder, this test is carried out under unlubricated condition.

Composition to the abrasion powder that produces in this rub(bing)test is investigated, results verification is subjected to the influence of the contained trace ingredients of the nickel cold rolling coil that uses as disk to: the composition of abrasion powder, particularly when the nickel cold rolling coil that uses boracic not during as disk, oxygen concn height in the abrasion powder, when using when containing nickel cold rolling coil that trace B forms as disk, the oxygen concn in the abrasion powder is low in addition.

The energy dispersion type x-ray spectrometry device (SEM-EDX) that utilizes the band scanning electron microscope carries out compositional analysis to the abrasion powder of gained in the test of using the nickel cold rolling coil of boracic not in the formation of disk, and it be the results are shown in Fig. 1.

In this is analyzed, except the iron that detects nickel and trace, also detect the peak of oxygen, be basis when carrying out quantitative analysis with the peak of this oxygen, confirmed the oxygen of 27 atom %.Think that oxygen in the abrasion powder is mainly as nickel oxide [NiO] or nickel hydroxide [Ni (OH) ₂] exist, but in any chemical formula the oxygen level of compound (except hydrogen) all more than 27 atom %.

However, thinking that the oxygen level of abrasion powder among Fig. 1 is that the reason of 27 atom % is that the abrasion powder is not to be pure compound, is nickel oxide or nickel hydroxide or their mixture and the mixture of the metallic nickel that does not form compound such as oxide compound.

On the other hand, Figure 2 shows that the abrasion powder when the nickel cold rolling coil that utilizes SEM-EDX to analyze use is contained 15ppm boron (utilizing inductively coupled plasma (ICP) emmission spectrum spectroscopy apparatus to carry out quantitatively) is as disk carries out the result of compositional analysis.

By this Fig. 2 as can be known, being used for the peak that abrasion powder that the rub(bing)test of disk produces substantially only confirms nickel at the nickel cold rolling coil with boracic, is basis when carrying out quantitative analysis with the peak of the oxygen of trace, only confirms the oxygen of 5 (± 3) atom %.

Hence one can see that, and boron has suppressed the oxide compound of nickel.

In addition, by SEM the form of abrasion powder is observed, results verification arrives: its form is according to the difference of the oxygen level in the abrasion powder and difference, in the less abrasion powder of oxygen, each particle has an independent existence, and in the more abrasion powder of oxygen, tiny particle aggregation and form big particle.

In addition, with littler when pushing load (1kgf) and implementing same rub(bing)test, for the disk of boracic not, though can confirm the generation of abrasion powder, the disk that contains trace B (15ppm) is confirmed less than the abrasion powder.

Think that its reason is, on the surface of the disk of boracic not, oxidized by nickel on the fresh surface that is produced that rubs, this oxide compound is assembled while coming off and is formed the abrasion powder, and for the disk that contains boron, on the surface of disk, the oxidation of nickel is suppressed, and does not particularly produce the abrasion powder under the less condition of contact pressure.

Also can confirm thus: for operability cold rolling in the manufacturing that prevents the nickel cold rolling coil reduces, importantly contain the boron of regulation, simultaneously the contact pressure between working roll and the rolling stock (nickel coiled sheet) is kept less.

(about the research of the manufacture method of nickel cold rolling coil)

Via the refining procedure in the fusion operation of utilizing the real machine electric furnace and the vacuum oxygen decarburization process (VOD), the materials different to boron content carry out ingot casting, make the slab of thick 150mm and wide 1000mm by Continuous casting process.

At this moment, in the refining procedure in VOD, become the mode of 4ppm and 15ppm and 89ppm, implement the interpolation of ferro-boron (alloy of iron and boron) according to the content of the boron of gained slab.

In addition, also make in the lump and do not add ferro-boron, only contain the slab of 1ppm boron.

After defectives such as the crackle cutting that will be present in steel slab surface is removed, under 1200 ℃ of Heating temperatures, carry out hot rolling, obtain the hot rolled coil of thickness 4mm.

In 820 ℃ atmosphere heat treatment furnace, this hot rolled coil is carried out continuous annealing, by sandblast (shot blast) and the pickling of nitre fluoric acid oxide skin is removed then, obtain the hot-roll annealing plate.

Use this hot-roll annealing plate, carried out cold rolling test, but except part test,, in 820 ℃ AX environmental gas, continuously the coiled sheet that is cold-rolled to 0.8mm from thickness 0.2mm is carried out clean annealing, as the evaluation coiled sheet for the coiled sheet length that extends.

Under the condition shown in the following table 7, this hot-roll annealing plate (or above-mentioned evaluation coiled sheet) is implemented the cold rolling of 3 passages or 4 passages, make the nickel cold rolling coil.

The condition of surface of the nickel cold rolling coil after each passage and the surface of working roll (WR) are carried out visual observation, it be the results are shown in table 7.

In addition, utilize radius (" the WR radius " in the table: R) calculate and obtain contact arc length (L=(R * Δ h) of working roll with thickness of slab reduction (Δ h) ^0.5), simultaneously by rolling load (" the initial stage rolling load " in the table: F) (F/W/L) obtain average roll pressure divided by plate wide (W) and the contact arc length (L) obtained by aforementioned calculation.

In addition, obtain the value of " 77+0.58X " in the lump by accumulative total draft (X),, compare with the average roll pressure of trying to achieve before as the rolling pressure higher limit.Show the result in table 7.

Create conditions down at the nickel cold rolling coil shown in the sequence number 1～3, do not see the accumulation of rolling abrasion powder on the surface of working roll, also do not observe the bad such problem of pattern defect, gloss of the nickel cold rolling coil that causes owing to this rolling abrasion powder.

On the other hand, in the example of boron content less than the sequence number 4 of 4ppm, because the content of boron is insufficient, thereby as seen by the pattern defect on the surface that transfer printing caused of the rolling abrasion powder of accumulative.

In addition, in the passage of rear section side, owing to become average roll pressure above the rolling pressure higher limit, thereby can confirm the accumulation of nickel powder at work roll surface, the result has reduced the surface gloss of nickel cold rolling coil.

And, along with rolling carrying out, the rapid increase of visible rolling load.

In addition, in the example of sequence number 5 and 6, when the average roll pressure that becomes above the rolling pressure higher limit, can confirm the accumulation of nickel powder, found that the surface gloss that has reduced the nickel cold rolling coil at work roll surface.

Can confirm thus,, make average roll pressure (kgf/mm simultaneously by containing the boron of specified amount ²) value be below the prescribed value, thereby can more positively prevent the reduction of the operability in cold rolling.

In addition, the data drawing listization that will gather based on the rolling real result in the real machine is shown in Fig. 3 with it.

In the chart example of this Fig. 3, black circles is represented is to implement the situation that visible rolling abrasion powder is piled up on working roll when cold rolling with this understanding, and white circle is represented is to implement not see when cold rolling the situation that rolling abrasion powder is piled up on working roll with this understanding.

In addition, dotted line represents to make accumulative total draft (total draft) for variable " red ", when average roll pressure is variable " pm ", with the straight line of the function representation of " pm=77+0.58red ".

Hence one can see that, by making average roll pressure (kgf/mm ²) value be below the 77+0.58X (in addition, X is the value of the accumulative total draft of this passage, and unit is " % "), thereby can more positively prevent the reduction of the operability when cold rolling.

[table 7]

" WR " expression " working roll " in the ※ table.

※ 1 contact arc length (mm)=(R * Δ h) ^0.5

※ 2 average roll pressures=(F/W/L) * 1000={F/W/ (R * Δ h) ^0.5} * 1000

※ 3 rolling pressure higher limit=77+0.58X

As can be known as implied above, nickel cold rolling coil of the present invention can suppress the problem that caused by rolling abrasion powder in the cold rolling process.

In addition, by The above results also as can be known, the problem that the manufacture method of nickel cold rolling coil of the present invention owing to can suppress is caused by rolling abrasion powder, thereby can expect high productivity and output.

＜＜estimate 3〉〉

(about adding the effect of boron)

Gather nickel thin plate is in the past cut apart the white powder that is produced when cutting off, it is carried out esca analysis.

In addition, similarly use ESCA to analyze, it be the results are shown in Fig. 4, Fig. 5 to the surface of in the past nickel thin plate with the surface that specified amount contains the nickel thin plate that boron makes as material composition.

(a) among the figure is the analytical results of white powder, (b) is the analytical results of nickel thin plate in the past, (c) is the analytical results of the nickel thin plate of boracic.

In general, the oxidized overlay film in metallic surface, promptly covered by metal oxide.

Think too that for the nickel thin plate its surface is covered by nickel oxide [NiO].

In the esca analysis result of Fig. 4, cut off white powder (a) that operation gathers at oxyhydroxide [Ni (OH) by cutting apart ₂] the clear and definite peak of position display, the surface coating of nickel thin plate (b) in the past presents the peak of oxyhydroxide too.

Think that thus white powder is the product that the surface coating of nickel thin plate comes off, and this surface coating be oxide compound [NiO] absorb in the atmosphere moisture through the time be varied to oxyhydroxide [Ni (OH) ₂] product.

In addition, oxide compound of nickel (NaCl type structure) and oxyhydroxide (CdI ₂The type structure) structurally different, think because the latter is a laminate structure, thereby not anti-shear-stress.That is, think owing to have nickel hydroxide in the surface coating, thereby overlay film becomes fragile, so the generation of white powder increases.

In order to address the above problem, as long as think and can suppress the nickel oxidation, then the nickel hydroxide amount in the surface coating reduces, and can reduce and cut apart the generation that cuts off the white powder in the operation.

Inhibition method to the surface oxidation (generation of oxide compound) of nickel is studied, and found that by adding oxidizing potential in advance to be lower than the element of nickel, to make the preferentially oxidation of this element in heat treatment process, thereby can suppress the oxidation of nickel.

Oxidizing potential is lower than nickel and can the trace unit that make an addition in the nickel have boron, silicon, aluminium, titanium, manganese, magnesium, calcium etc.

Wherein, the velocity of diffusion of boron in metal soon, effective especially.

Because it is the most surperficial that boron promptly diffuses in heat treated process, earlier oxidized than nickel, thereby easily in surface coating, concentrate.

Its result can suppress the formation of nickel oxide, and the also attenuation of the thickness of simultaneous oxidation overlay film is difficult to take place be varied to oxyhydroxide and the embrittlement of the surface coating that causes by this oxide compound.

Among (c) of Fig. 4 (the nickel thin plate of boracic), the strong peak of the position display of metallic nickel does not almost observe the peak of the oxyhydroxide as product (b) in the past.

And, be somebody's turn to do in (c), as shown in Figure 5, can confirm tangible peak in the zone of boron.

That is, as can be known, the most surperficial spissated state of boron that becomes of this nickel thin plate, the generation of nickel oxide is suppressed.

(estimating the making of sample)

The nickel thin plate of sample No.1～16 shown in the making table 8 is also estimated.

At first, vacuum oxygen decarburization process (VOD) technology by having used electric furnace is carried out ingot casting to the nickel of principal constituent, in this ingot casting process, adds boron and makes it reach the amount shown in the table 1 (B addition).

The gained slab is carried out hot rolling, carry out afterwards cold rollingly reaching the value (thickness of slab) of table 8, make the nickel thin plate until final thickness of slab.

Gained nickel material is heat-treated by bright annealing oven.This moment, environmental gas composition, dew point and the thermal treatment temp of annealing furnace were as shown in table 8.

(evaluation 3-1: surface analysis)

Composition for the surface coating of the nickel thin plate of investigating each sample No. has carried out esca analysis, the amount of investigation nickel and boron.

For the nickel zone, carry out the peak and resolve, the state ratio of investigation oxide compound and metal.

At this moment, the oxide ratio of nickel is low more, and then presentation surface oxidation overlay film is thin more.

Show the result in table 8.

By shown in this table 8 as can be known, esca analysis is carried out on the surface of nickel thin plate that the addition of boron is surpassed sample No.1～11 of 0.0004 quality %, result, the boron concentration minimum in the surface coating be 2.1 atom %, be 20.1 atom % to the maximum.

Boron all is present in the surface with the state that is in a ratio of high concentration with addition, and boron takes place on the surface to concentrate as can be known.

On the other hand, the boron addition is no matter the nickel thin plate of sample No.12～16 of 0.0004 quality % has or not thermal treatment, does not all detect boron from surface coating.

In addition, Fig. 6 represents the relation of boron addition and surface boron concentration.In addition, the data shown in the example of black triangle are the most surperficial boron concentration situation less than 1 atom %, and the data shown in the example of black circles are the above situation of 1 atom % for the most surperficial boron concentration.

As known in the figure, increase the boron addition more, then surface boron concentration also increases more.

In addition, Figure 7 shows that the figure of the relation of rendered surface boron concentration and nickel oxide ratio.In addition, the data shown in the example of black triangle are the most surperficial boron concentration situation less than 1 atom %, and the data shown in the example of black circles are the above situation of 1 atom % for the most surperficial boron concentration.

As known in the figure, surface boron concentration is high more, and the ratio of nickel oxide tends to reduce more.That is, the surface that can confirm by boron concentrates, and has suppressed the oxidation of nickel.

(evaluation 3-2: the generation of white powder)

Using the identical shut-off device of cutting apart with the nickel thin plate (200mm wide plate roll) of each sample No. when division processing becomes 50mm wide, observe the generation of white powder, with the situation that do not produce white powder for " zero " though, with produce for very a spot of situation for " △ ", judge for " * " with the situation of a large amount of generations.

Show the result in table 8.

In addition, in the addition of boron surpassed the sample of 0.0004 quality %, No.4 and No.6 had produced white powder a little cutting apart to cut off in the operation, but be practical no problem level.In addition there is no the generation of white powder.

On the other hand, the boron addition is no matter the nickel thin plate of sample No.12～16 of 0.0004 quality % has or not thermal treatment all to produce a large amount of white powders, and the result is not preferred in appearance.

(evaluation 3-3: connectivity)

The nickel thin plate ultrasonic wave of each sample No. is bonded on the Copper Foil of thickness 10 μ m, is that " △ " judges with the situation that can easily engage for " zero ", with difficult situation about engaging.

Show the result in table 8.

The nickel thin plate that the addition of boron surpasses sample No.1～11 of 0.0004 quality % all obtains good connectivity.

On the other hand, the boron addition is the problem that the nickel thin plate of sample No.12～16 of 0.0004 quality % has following aspect: in order to obtain and the equal connectivity of the nickel thin plate of sample No.1～11, need to increase joint load etc.

[table 8]

By this evaluation result as can be known, the surface texture excellence of nickel material of the present invention.

As mentioned above, the present invention can make the less nickel materials of defective such as crackle, flaw efficiently.

Claims

1. a nickel material is characterized in that, contains the boron that nickel more than 99% and 3ppm are above and 110ppm is following in mass.

2. nickel material according to claim 1, wherein, the content of described boron is more than the 4ppm and below the 100ppm.

3. nickel material according to claim 1 and 2, wherein, the concentration of the most surperficial boron is more than the 1 atom %.

4. the manufacture method of a nickel material is characterized in that, makes the nickel contain in mass 99% or more and 3ppm is above and the slab of the boron below the 110ppm, and this slab is rolled and makes tabular nickel material.

5. the manufacture method of nickel material according to claim 4, wherein, the nickel that uses described slab to make to contain in mass 99% or more and 4ppm is above and the hot rolled coil of the boron that 100ppm is following is implemented cold rolling more than 1 time to this hot rolled coil, and manufacturing is as the cold rolling coil of described nickel material.

6. the manufacture method of nickel material according to claim 5, wherein, according to the average roll pressure (kgf/mm in each passage ²) the value mode that when the value of the accumulative total draft of establishing this passage is X (%), is no more than (77+0.58X) implement described cold rolling.

7. according to the manufacture method of claim 5 or 6 described nickel materials, wherein, described cold rolling coil is implemented thermal treatment, the concentration of the most surperficial boron is concentrated into more than the 1 atom %, described thermal treatment is implemented under the following conditions: the dew point that forms more than a kind in using nitrogen, hydrogen and argon gas is in the environmental gas below-30 ℃, and is implementing more than 450 ℃ and under any temperature in the scope below 900 ℃.